I have been really lazy for the past month or so and haven’t really been blogging, even though there have been some really cool science news stories and new papers published. In a half-hearted attempt to get back on the blogging horse, here are some links to a few interesting BBC science stories:
 
Positive news for the rare large heath butterfly: a population has been established after captive breeding and reintroduction!
 
http://www.bbc.co.uk/news/science-environment-36865426
 
Amazonian droughts stop the vast rainforest being a carbon sink. Not great news for increased extreme weather events and climate changes… positive feedback loop?
 
http://www.bbc.co.uk/news/science-environment-36856428
 
Cuckoo decline mapped for the first time:
 
http://www.bbc.co.uk/news/science-environment-36837641
 
Honeyguides and humans ‘speak’ to each other! (although the babblers come to a whistle, so I’m not super surprised that this type of behaviour exists):
 
http://www.bbc.co.uk/news/science-environment-36854465
 
Abstract and link to the paper in the last news story:
 
Spottiswoode et al (2016) Reciprocal signaling in honeyguide-human mutualism. Science, 353:387-389
Greater honeyguides (Indicator indicator) lead human honey-hunters to wild bees’ nests, in a rare example of a mutualistic foraging partnership between humans and free-living wild animals. We show experimentally that a specialized vocal sound made by Mozambican honey-hunters seeking bees’ nests elicits elevated cooperative behavior from honeyguides. The production of this sound increased the probability of being guided by a honeyguide from about 33 to 66% and the overall probability of thus finding a bees’ nest from 17 to 54%, as compared with other animal or human sounds of similar amplitude. These results provide experimental evidence that a wild animal in a natural setting responds adaptively to a human signal of cooperation.

In the spirit of many of my previous blogs I am going to write about a new paper written by someone I know. This may sound like some sort of nepotism, not that many people really read my blog, but this new paper has actually made quite a splash and so I’m really just following a great new science story. If you want to see some of the other coverage then click on these links: Science, Sci News, Science Daily, or PLoS Blogs. (The abstract and link to the paper in question is at the bottom of the blog)
 
This new piece of research is a product of the Hot Birds team at the Fitz in Cape Town, with Tanja van de Ven (lead author) spending many gruelling hours in the Kalahari heat with fairly complex equipment. The team, and Tanja’s, aim is to investigate how birds cope with rising temperatures using species that already exist in the hard thermal conditions of the Kalahari. One of their papers looked at the impact of heat stress on foraging in pied babblers. However, Tanja’s work focuses on yellow-billed hornbills, a species of bird that nests inside trees, with the female sealing herself into this cavity. This reproductive adaptation is great for protecting your eggs and female from predators but it can limit your ability to control your temperature, as you’re pretty stuck (it also means that the female and chicks are 100% dependent on the male for their nutritional needs – such a cool system for male-female and parent-offspring dynamics!!!).
 
The obvious feature of this bird, hopefully you have either clicked on the link or already know what a hornbill looks like from your bird knowledge or from childhood exposure to the Lion King, is that they have a massive long bill. The beak of a bird is not just lifeless tissue like finger nails but very much a living structure and as such has a profusion of blood vessels. Just like the thermoregulation that takes place in humans, where capillaries close to the surface are constricted or relaxed to either conserve or radiate heat, hornbills appear to have the same ability with the blood vessels in their beak. As the ambient air temperature increases more blood is pushed into the hornbill’s beak, allowing heat to be lost through radiative heat transfer. This is similar to toucans, as a recent study has found, but in the toucan this process accounts for upto 60% of non-evaporative heat loss compared to just 8% in the hornbill. There are a number of potential reasons for this: the toucans have much larger bills, hornbills have a harder bill (maybe an ecological adaptation to how they forage?) and toucans start dilating their blood vessels at lower temperatures.
 
This type of research is crucial for understanding how organisms are physiologically adapted to their environment. It enables researchers to better understand the environmental limits that a species may be able to cope with and allow predictions as to the impacts of climate change. It’s also pretty cool too.
 
 
van de Ven et al. (2016) Regulation of heat exchange across the hornbill beak: functional similarities with Toucans? PLoS One
 
Beaks are increasingly recognised as important contributors to avian thermoregulation. Several studies supporting Allen’s rule demonstrate how beak size is under strong selection related to latitude and/or air temperature (Ta). Moreover, active regulation of heat transfer from the beak has recently been demonstrated in a toucan (Ramphastos toco, Ramphastidae), with the large beak acting as an important contributor to heat dissipation. We hypothesised that hornbills (Bucerotidae) likewise use their large beaks for non-evaporative heat dissipation, and used thermal imaging to quantify heat exchange over a range of air temperatures in eighteen desert-living Southern Yellow-billed Hornbills (Tockus leucomelas). We found that hornbills dissipate heat via the beak at air temperatures between 30.7°C and 41.4°C. The difference between beak surface and environmental temperatures abruptly increased when air temperature was within ~10°C below body temperature, indicating active regulation of heat loss. Maximum observed heat loss via the beak was 19.9% of total non-evaporative heat loss across the body surface. Heat loss per unit surface area via the beak more than doubled at Ta > 30.7°C compared to Ta < 30.7°C and at its peak dissipated 25.1 W m-2. Maximum heat flux rate across the beak of toucans under comparable convective conditions was calculated to be as high as 61.4 W m-2. The threshold air temperature at which toucans vasodilated their beak was lower than that of the hornbills, and thus had a larger potential for heat loss at lower air temperatures. Respiratory cooling (panting) thresholds were also lower in toucans compared to hornbills. Both beak vasodilation and panting threshold temperatures are potentially explained by differences in acclimation to environmental conditions and in the efficiency of evaporative cooling under differing environmental conditions. We speculate that non-evaporative heat dissipation may be a particularly important mechanism for animals inhabiting humid regions, such as toucans, and less critical for animals residing in more arid conditions, such as Southern Yellow-billed Hornbills. Alternatively, differences in beak morphology and hardness enforced by different diets may affect the capacity of birds to use the beak for non-evaporative heat loss.

 
Everyone in the UK seemed to get very excited about the first British astronaut, Tim Peake. I feel bad, but space just doesn't fill me with the sense of wonder and excitement and so I just couldn’t get into the fanfare surrounding the launch. There is also the oddity that although Tim Peake is the first British astronaut, he isn’t actually the first Briton in space: that honour goes to Helen Sharman. I’m not trying to put a downer on the whole scientific endeavour, but it just doesn’t float my boat but I’m sure that Brian Cox is going crazy about it!
 
Some good news this week about nitrogen dioxide (NO2) and Europe’s ability of reducing its emissions. NO2 is not very good for public health and increases the amount of ozone (O3) at ground level (it’s great when it’s in the upper atmosphere but not so great when we can breathe it in).
Results of tracking of NO2 production have recently been published, and although the overall trend isn’t great at least it show a significant drop in emissions from Europe and the US. I’m trying to see the positives instead of the negatives!

For my undergrad thesis I worked on Chalkhill Blue butterflies at a wildlife reserve in Bedfordshire. Like most people growing up in Britain my experience of butterflies was mainly seeing the odd Cabbage White float over my garden. But the reserve where I did my research was teaming with 10s of species and huge number of these magical insects. Walk along a hedge row and it would erupt in front of you with clouds of blues, oranges, yellow and greens as the butterflies swarmed around you. Those experiences make the news the 76% of Britain’s butterflies are in decline very saddening. Some species and some areas are doing fine but for the majority of these enigmatic species the trend is downwards. Chris Packham spoke well on the Today Programme (01:20:38) about the possible reasons for the decline and the need for research into why it’s happening and how we can stop it.

Darwin's finches are one of the most emblematic images of the voyage of the Beagle and are an integral part of the story that has grown up around how Darwin discovered the Theory of Natural Selection. The diversity of the beaks of these birds has become part of the fabric of biological history. I first heard about the issues facing Darwin’s finches while listening to an episode of Radiolab: LINK (it was part of a larger episode on the Galapagos). These iconic birds are facing a huge threat from invasive flies that lay their eggs in their nest’s and whose larvae attack the nostrils of the finch nestlings. Researchers from the University of Massachusetts Darmouth have been studying the medium ground finch and modelling how these parasites will impact the population and the results are not good: they could be extinct within 50 years. But the models also show that if you reduce the risk of infestation occurring, and the researchers suggest using cotton soaked in pesticide that the birds can incorporate into their nests. But in a cool twist this new parasite-host relationship has resulted in a change in behaviour in a closely related species with increased begging rate from nestlings when parasitized, resulting in them being fed more and more likely to survive!
 
A couple of other really cool science news stories this week: hummingbird heat loss and elephants and earthquakes.